Filter cleaning is becoming more important as the requirements regarding filtration levels are increased. Thus, cleaning the filter becomes important in order to maintain a high air flow through the filter (i.e. to avoid that the filter is getting clogged).
Today, several systems are available. WO 2008/014794 A1 discloses a system with a large solenoid opening a valve positioned above the filter. When opening the valve, the air flows into the tank due to the effect of under pressure. Thus, the filter is thereby cleaned by “blowing” the dust into the tank. Generally, this system has proven to be effective, but complex and expensive control electronics are required.
WO 2010/028787 A1 discloses another system, said system being effective, but highly complex and expensive as it requires 2 filters, an electrical actuated direction valve and a solenoid valve to open for the “back flow” in order to clean the filter. Furthermore, complex and expensive control electronics are needed to render the system operational.
GB 1 259 557 A discloses an air filtering installation comprising a motor, which rotates a hammer, said hammer being fastened to a leaf-spring. During the rotation, the hammer slides along the guide surface and edge, thus resulting in the conversion of the rotational movement of the hammer into an axial movement of said hammer. The hammer controls the tension of the leaf-spring, and thereby the opening of the plate valve. However, leaf-springs possess some disadvantages, i.e., proper adjustment is difficult, and, thus, alternatives are needed.
As apparent from the above, simple, effective and less expensive filter cleaning systems are needed. By the present invention, such is provided.